EUREKA!! I just did.
I had the same problem with my macbook pro late 2011 edition ever since I have upgraded it to High Sierra and my battery is dead.
I update to MacOs 10.13.4 and still the same problem (the macbook thinks its a desktop it's not showing trackpad properties in System Preference panel) and still looking for at bluetooth trackpad
So, I put my bluetooth trackpad (from my Imac) to work with my MacbookPro so with this trackpad I reach all settings and the real trackpad catch the same settings of the extra trackpad.
When I turn-off the extra trackpad my settings there was still ok, even if the (without the extra trackpad) the settings panel doesn't see my real trackpad
So, I'm happy with that until I figure out another solution.
Best Regards